Pages is a functional word processor if that's your task. I've never used Keynote, but I've heard it is every bit as good as Powerpoint.
Regrettably, Numbers is not even close to Excel. For example, Excel handles the .csv files I work with every day in the blink of an eye, perfectly every time. Numbers dumps all the data in a comma-separated-value table into a single cell, which defeats the whole point of a spreadsheet.
Numbers is nothing compared to Excel. That's too bad.